High-pressure bevel gear pump

Abstract

The invention relates to a gear pump, in particular to a high-pressure bevel gear pump. According to the high-pressure bevel gear pump, the transmission gear of the high-pressure gear pump is changed into the bevel gear from a straight gear, so that the meshing stability of the high-pressure gear pump can be remarkably improved, the impact is reduced, and the noise of the gear pump and the flow pulsation of fluid output are reduced; by adopting the special oil inlet oil duct section design, the high-pressure area is further expanded, the axial stress of the gear shaft of the high-pressure bevel gear pump is reduced, the bending deformation of the gear shaft is reduced, the bearing capacity of the high-pressure gear pump is improved, and the service life of the high-pressure gear pump is prolonged; by adopting a middle sealing axial automatic compensation technology, high pressure and high efficiency of the high-pressure bevel gear pump can be realized.

Description

Technical Field

[0001] The invention relates to a gear pump, in particular to a high-pressure helical gear pump. Background Art

[0002] In the prior art, the transmission gears of hydraulic gear pumps generally used in medium- and high-pressure systems are externally meshing spur gears. Only a few low-pressure gear pumps are designed with helical gears to reduce noise. For a long time, to improve the mass-power density of gear pumps, high-pressure gear pumps have been designed as hydraulic devices with a small number of teeth and a large module. Spur gears can effectively meet the needs of gear sealing, but they also bring many disadvantages. The mesh overlap coefficient of the gears should not be too large, generally between 1.05 and 1.2. If it is too large, on the one hand, the number of gear teeth needs to be increased, which increases the size of the gear pump; on the other hand, it can cause oil entrapment and cavitation. In addition, when the gears rotate at high speed, the hydraulic fluid is squeezed from the inlet to the outlet through the sealed cavity between the teeth and the housing. The regularly discharged hydraulic fluid resonates with the mechanical components, generating fluid energy with regular pressure pulsations, which in turn generates noise. In turn, the hydraulic fluid energy with pressure pulsations causes regular shocks in the gear transmission process, which in turn affects the smoothness of the transmission and increases the loss of input torque.

[0003] In order to solve the oil trapped and cavitation problems of gear pumps, general high-pressure gear pumps will have an oil drain groove on the side panel that is symmetrical between the middle surface of the master and driven gears and connected to the oil pressure chamber. Adding an oil drain groove can solve certain noise problems, but it will cause certain leakage and affect the volumetric efficiency.

[0004] In order to improve volumetric efficiency and reduce leakage between the side plate and the gear, axial compensation technology is a common design method in the design of spur high-pressure gear pumps. However, since the helical gears will generate axial force on the gears during the transmission process, the side plate will be pushed to the side away from the side plate, and the requirements for compensation technology will be more complicated. Domestic related literature generally designs it as a fixed gap. There is no solution or technical inspiration for using axial compensation under the existing technology.

[0005] In addition, in order to reduce the pressure-bearing area of ​​the casing, the high-pressure oil is sealed in the cavity between the side plates, the casing, and the gears. The technical solution of using the middle sealing technology is also often used in spur gear high-pressure gear pumps, but technical personnel in this field generally believe that this technology cannot and does not need to be used in helical gear pumps. Summary of the Invention

[0006] In order to solve the problems of the prior art, the present invention provides a high-pressure helical gear pump, which can significantly improve the meshing smoothness of the high-pressure gear pump, reduce impact, and reduce the noise of the gear pump and the flow pulsation of the fluid output by improving the transmission gear of the high-pressure gear pump from a spur gear to a helical gear; by adopting a special oil inlet oil channel cross-section design, the high-pressure area is further expanded, the axial force of the gear shaft of the high-pressure helical gear pump is reduced, and the bending deformation of the gear shaft is reduced, thereby improving the load-bearing capacity and service life of the high-pressure gear pump; by adopting the middle seal axial automatic compensation technology, high pressure and high efficiency of the high-pressure helical gear pump can be achieved.

[0007] The technical solutions adopted in the present invention are as follows: A high-pressure helical gear pump comprises a front cover and a rear cover body, wherein the front cover and the rear cover body are fixedly connected together by bolts and positioned by positioning pins, a sealing ring is installed between the front cover and the rear cover body, and the front cover and the rear cover body are also provided with an oil pressure chamber and an oil suction chamber; the rear cover body has an "8"-shaped inner cavity inside, and a driving gear shaft and a driven gear shaft are respectively installed on the upper and lower sides of the "8"-shaped inner cavity, and a helical gear that meshes with each other is provided between the driving gear shaft and the driven gear shaft. The shaft passes through the front cover and extends to the outside to connect to the external power input end. A retaining ring, a deep groove ball bearing and an oil seal are arranged between the front end of the driving gear shaft and the front cover from the outside to the inside. Support bearings are installed on the upper and lower ends of the driving gear shaft and the driven gear shaft respectively. The meshing end side plate and the meshing end side plate are installed on the front and rear sides of the helical gear respectively. The meshing end side plate and the meshing end side plate are in the shape of an "8" as a whole, which is consistent with the shape of the "8"-shaped inner cavity inside the rear cover body, and a closed cavity is formed after installation.

[0008] Preferably, the meshing end side plate is provided with a meshing end side plate high-pressure unloading groove, a meshing end side plate low-pressure unloading groove and a meshing end side plate groove on one side in contact with the end faces of the driving gear shaft and the driven gear shaft, wherein the meshing end side plate groove is connected to the meshing end side plate high-pressure unloading groove, and the meshing end side plate groove forms an angle α with the horizontal reference line of the two gear axes on both sides of the driving gear shaft and the driven gear shaft; the meshing end side plate is provided with a meshing end side plate high-pressure unloading groove, a meshing end side plate low-pressure unloading groove and a meshing end side plate groove on one side in contact with the end faces of the driving gear shaft and the driven gear shaft, wherein the meshing end side plate The groove is connected to the high-pressure unloading groove of the meshing end side plate, and the horizontal reference line angle formed by the meshing end side plate groove on both sides of the driving gear shaft and the driven gear shaft and the two gear axes is β; the angle difference formed by the horizontal reference line angle β and the horizontal reference line angle α is consistent with the angle difference θ formed by the driving gear shaft and the driven gear shaft at the meshing end and the meshing end respectively projected on the meshing end side plate plane and the meshing end side plate plane, that is, θ=β-α; the projection line of the oil inlet channel section of the rear cover body in the "8"-shaped inner cavity is parallel to the projection lines of the driving gear shaft and the driven gear shaft in the "8"-shaped inner cavity.

[0009] Preferably, a meshing end side plate "3"-shaped groove is provided on the side of the meshing end side plate facing away from the bevel gear, and is interconnected with the meshing end side plate high-pressure unloading groove through the meshing end side plate oil inlet groove, the meshing end side plate oil inlet hole, the outer edge of the meshing end side plate "3"-shaped groove and the rear cover body cavity form a closed meshing end large "3"-shaped compensation area, and a special-shaped retaining ring I and a special-shaped sealing ring I with the same shape as the groove are installed in the meshing end side plate "3"-shaped groove; a meshing end side plate "3"-shaped groove is provided on the side of the meshing end side plate facing away from the bevel gear, and is interconnected with the meshing end side plate high-pressure unloading groove through the meshing end side plate oil inlet groove, the meshing end side plate oil inlet hole, the outer edge of the meshing end side plate "3"-shaped groove and the rear cover body cavity form a closed meshing end large "3"-shaped compensation area, and a special-shaped retaining ring II and a special-shaped sealing ring II with the same shape as the groove are installed in the meshing end side plate "3"-shaped groove.

[0010] The beneficial effects brought about by the technical solution provided by the present invention are: 1. A pair of helical gears is used instead of the traditional spur gear transmission to improve the gear meshing characteristics of the gear pump. By increasing the gear overlap, the gear meshing stability is improved, the impact is reduced, and the noise and flow pulsation of the fluid output are reduced.

[0011] 2. The middle seal axial compensation technology is adopted to achieve high pressure and high efficiency of the helical gear pump.

[0012] The present invention improves the transmission gear of the high-pressure gear pump from a spur gear to a helical gear, thereby improving the gear meshing stability, reducing impact, and reducing the noise of the gear pump and the flow pulsation of the fluid output; by adopting a special oil inlet oil channel cross-section design, the high-pressure area can be further expanded, the axial force of the gear shaft of the high-pressure helical gear pump can be reduced, the bending deformation of the gear shaft can be reduced, and the load-bearing capacity and service life of the high-pressure gear pump can be improved; by adopting the middle seal axial automatic compensation technology, high pressure and high efficiency of the high-pressure helical gear pump can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0014] Figure 1 This is a perspective view of the overall structure of a high-pressure helical gear pump of the present invention; Figure 2 for Figure 1 Left side view (without front cover); Figure 3 This is the front view of the side plate at the gear engagement end; Figure 4 This is the reverse side view of the gear meshing end plate; Figure 5 This is the front view of the side plate at the meshing end of the gear; Figure 6 , Rear view of the gear meshing end side plate Figure 7 for Figure 2 AA cross-sectional view (without internal parts and front cover); Figure 8 This is a transmission schematic diagram of a high-pressure helical gear pump of the present invention.

[0015] Figure 1 and Figure 2 Middle: 1. retaining ring, 2. front cover, 3. deep groove ball bearing, 4. oil seal, 5. bearing, 6. special-shaped retaining ring I, 7. sealing ring, 8. engaging end side plate, 9. engaging end side plate, 10. special-shaped retaining ring II, 11. driving gear shaft, 12. rear cover, 13. driven gear shaft, 14. special-shaped sealing ring I, 15. special-shaped sealing ring II, 16. oil suction chamber, 17. oil pressure chamber, 18. bolt, 19. positioning pin; 20. bevel gear.

[0016] Figure 3 and Figure 4Middle: 801, high-pressure unloading groove of the meshing end side plate, 802, low-pressure unloading groove of the meshing end side plate, 803, groove of the meshing end side plate, 804, oil guide hole of the meshing end side plate, 805, oil guide groove of the meshing end side plate, 806, "3"-shaped groove of the meshing end side plate; Figure 5 and Figure 6 Middle: 901, high-pressure unloading groove of meshing end side plate, 902, low-pressure unloading groove of meshing end side plate, 903, groove of meshing end side plate, 904, oil inlet hole of meshing end side plate, 905, oil inlet groove of meshing end side plate, 906, "3"-shaped groove of meshing end side plate; Figure 1 In the figure, line M is the projection line of the tooth top of the driving gear shaft on the horizontal plane, and line N is the projection line of the tooth top of the driven gear shaft on the horizontal plane; Figure 7 In FIG, the M' line is the projection line of the oil inlet passage section on the driving gear side of the 8-shaped inner cavity, and the N' line is the projection line of the oil inlet passage section on the driven gear side of the 8-shaped inner cavity. DETAILED DESCRIPTION

[0017] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Example 1

[0018] By attaching Figure 1 and attached Figure 2 It can be seen that this embodiment is a high-pressure helical gear pump for conveying high-pressure fluid, and its housing is composed of a front cover 2 and a rear cover body 12. The front cover 2 and the rear cover body 12 are positioned by a positioning pin 19 and are fixed together by a bolt 18. A sealing ring 7 is installed between the front cover 2 and the rear cover body 12. The driving gear shaft 11 and the driven gear shaft 13 are installed in the "8"-shaped inner cavity opened in the rear cover body 12. The driving gear shaft 11 extends after passing through the front cover 2 and is the power input end of the device, driving the rotation of the driving gear shaft 11. Between the driving gear shaft 11 and the front cover 2 From the output shaft end to the direction of the helical gear 20, a retaining ring 1, a deep groove ball bearing 3, and an oil seal 4 are sequentially installed. Support bearings 5 ​​are respectively installed at the two ends of the driving gear shaft 11 and the driven gear shaft 13, respectively, for supporting the normal rotation of the driving gear shaft 11 and the driven gear shaft 13. The support bearings 5 ​​here can be rolling bearings or sliding bearings, and do not affect the functional effect of the device; at both ends of the helical gear 20, an engaging end side plate 8 and an engaging end side plate 9 are respectively installed. The outer shape of the two side plates is "8"-shaped, which matches the outer shape of the inner cavity of the rear cover body 12 to form a closed cavity.

[0019] In order to achieve floating compensation of the engaging end side plate 8 and the engaging end side plate 9 in the cavity and seal the high pressure oil in the inner cavity of the rear cover body 12, Figure 3 and Figure 4It can be seen that a meshing end side plate "3"-shaped groove 806 is opened on the side of the meshing end side plate 8 facing away from the gear, and is connected to the meshing end side plate high-pressure unloading groove 801 through the meshing end side plate oil inlet groove 805 and the meshing end side plate oil inlet hole 804. The outer edge of the meshing end side plate "3"-shaped groove 806 and the inner cavity of the rear cover body 12 form a closed meshing end large "3"-shaped compensation area, and a special-shaped retaining ring I6 and a special-shaped sealing ring I14 with the same shape as the groove are installed in the meshing end side plate "3"-shaped groove 806; through Figure 5 and Figure 6 It can be seen that a meshing end side plate "3"-shaped groove 906 is opened on the side of the meshing end side plate 9 facing away from the gear, and is connected to the meshing end side plate high-pressure unloading groove 901 through the meshing end side plate oil inlet groove 905 and the meshing end side plate oil inlet hole 904. The outer edge of the meshing end side plate "3"-shaped groove 906 and the inner cavity of the rear cover body 12 form a closed large "3"-shaped compensation area, and a special-shaped retaining ring II10 and a special-shaped sealing ring II15 with the same shape as the groove are installed in the meshing end side plate "3"-shaped groove 906.

[0020] pass Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6It can be seen that the special feature of the structure of this embodiment is that the closed "3"-shaped compensation area of ​​the engaging end side plate not only overcomes the separation force of the engaging end side plate 8 relative to the driving gear shaft 11 and the driven gear shaft 13, but also overcomes the axial component force of the driven gear 13 acting on the engaging end side plate 8; the closed "3"-shaped compensation area of ​​the meshing end side plate not only overcomes the separation force of the meshing end side plate 9 relative to the driving gear shaft 11 and the driven gear shaft 13, but also overcomes the axial component force of the driven gear 13 acting on the engaging end side plate 8. 1 acts on the axial component of the meshing end side plate 9; in order to realize this design scheme, the meshing end side plate 8 is respectively provided with a meshing end side plate high pressure unloading groove 801, a meshing end side plate low pressure unloading groove 802 and a meshing end side plate groove 803 on the side that contacts the end faces of the driving gear shaft 11 and the driven gear shaft 13, wherein the meshing end side plate groove 803 is connected to the meshing end side plate high pressure unloading groove 801, and the meshing end side plate groove 803 is located between the driving gear shaft 11 and the driven gear shaft 13. The angle between the horizontal reference line formed by the two sides and the two gear axes is α; the meshing end side plate 9 is respectively provided with a meshing end side plate high pressure unloading groove 901, a meshing end side plate low pressure unloading groove 902 and a meshing end side plate groove 903 on the side that contacts the end faces of the driving gear shaft 11 and the driven gear shaft 13, wherein the meshing end side plate groove 903 is connected to the meshing end side plate high pressure unloading groove 901, and the meshing end side plate groove 903 is connected to the driving gear shaft 11 and the driven gear shaft 13 on both sides. The angle between the horizontal reference lines formed by the two gear axes is β; the angle difference formed by β-α is consistent with the angle difference θ formed by the driving gear shaft 11 and the driven gear shaft 13 being projected on the plane of the meshing end side plate 9 and the plane of the meshing end side plate 8 at the meshing end and the meshing end, respectively, that is, θ=β-α; the projection lines M' and N' of the oil inlet channel section of the rear cover body 12 in the "8"-shaped inner cavity are parallel to the projection lines M and N of the driving gear shaft 11 and the driven gear shaft 13 in the "8"-shaped inner cavity, respectively.

[0021] As attached Figure 8 As shown, the working process of this embodiment is as follows: The input power from the external prime mover drives the gear pump to rotate counterclockwise, that is, Figure 8 When the gear shaft 11 rotates in the direction shown, the oil is sucked from the oil suction chamber 16 and squeezed by the rotating driving gear shaft 11 and the driven gear shaft 13 to form pressure oil and discharged from the oil pressure chamber 17. Due to the effect of the fluid oil pressure, the driving gear shaft 11, the driven gear shaft 13, the meshing end side plate 8 and the meshing end side plate 9 will lean against the oil suction chamber 16 side of the "8"-shaped inner cavity of the rear cover body 12, that is, Figure 2On one side of the oil suction chamber 16, and on the other side of the oil pressure chamber 17, between the inner cavity of the rear cover body 12 and the gear pairs 11 and 13, and between the rear cover body 12 and the meshing end side plate 8 and the meshing end side plate 9, the gaps are sealed by the special-shaped retaining ring I, the special-shaped retaining ring II, the special-shaped sealing ring I and the special-shaped sealing ring II, respectively forming a "3"-shaped groove 806 of the reverse meshing end side plate and a "3"-shaped groove 906 of the meshing end side plate, and then respectively through the meshing end side plate oil lead hole 804, the meshing end side plate oil lead hole 904 and the meshing end side plate height The pressure relief groove 801 and the high-pressure relief groove 901 of the meshing end side plate are connected, and the pressure oil from the high-pressure fluid is drawn to form oil pressure to generate compensation thrust, which pushes the meshing end side plate 8 and the meshing end side plate 9 toward the gear pair end faces of the driving gear shaft 11 and the driven gear shaft 13 respectively, overcoming the axial separation force caused by the high-pressure oil pressure from the front of the meshing end side plate 8 and the meshing end side plate 9 and the axial component force of the driving gear shaft and the driven gear shaft acting on the meshing end side plate 9 and the meshing end side plate 8 respectively, maintaining the axial seal of the gear pump and realizing the axial hydraulic floating compensation of the gear pump.

[0022] When the input power from the external prime mover drives the gear pump to rotate clockwise, it can be realized by simply flipping the engagement end side plate 8 and the engagement end side plate 9 180 degrees up and down, and exchanging the oil suction chamber 16 and the oil pressure chamber 17 of the rear cover body 12. The detailed working conditions are the same as above and will not be repeated here.

[0023] The gear engagement end referred to in the scheme of the present invention is the end of the gear that first enters into engagement when viewed from the oil pressure chamber, and the gear engagement end is the end of the gear that last enters into engagement when viewed from the oil pressure chamber.

[0024] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-pressure helical gear pump, comprising a front cover and a rear cover, wherein the front cover and the rear cover are fixedly connected together by bolts and positioned by positioning pins, a sealing ring is installed between the front cover and the rear cover, and the front cover and the rear cover are also provided with an oil pressure chamber and an oil suction chamber; characterized in that: The rear cover body has an "8"-shaped inner cavity inside, and the upper and lower sides of the "8"-shaped inner cavity are respectively installed with a driving gear shaft and a driven gear shaft, and mutually meshing helical gears are arranged between the driving gear shaft and the driven gear shaft. The driving gear shaft passes through the front cover and extends to the outside to connect the external power input end. A retaining ring, a deep groove ball bearing and an oil seal are sequentially arranged between the front end of the driving gear shaft and the front cover from the outside to the inside. Support bearings are respectively installed on the upper and lower ends of the driving gear shaft and the driven gear shaft, and an engaging end side plate and an engaging end side plate are respectively installed on the front and rear sides of the helical gear. The engaging end side plate and the engaging end side plate are overall in the shape of "8", which is consistent with the outer shape of the "8"-shaped inner cavity inside the rear cover body, and a closed cavity is formed after installation.

2. A high-pressure helical gear pump according to claim 1, characterized in that: The meshing end side plate is provided with a meshing end side plate high pressure unloading groove, a meshing end side plate low pressure unloading groove and a meshing end side plate groove on one side of the engaging end side plate that contacts the end faces of the driving gear shaft and the driven gear shaft, wherein the meshing end side plate groove is connected to the meshing end side plate high pressure unloading groove, and the meshing end side plate groove forms an angle α with the horizontal reference line of the two gear axes on both sides of the driving gear shaft and the driven gear shaft; the meshing end side plate is provided with a meshing end side plate high pressure unloading groove, a meshing end side plate low pressure unloading groove and a meshing end side plate groove on one side of the engaging end side plate that contacts the end faces of the driving gear shaft and the driven gear shaft, wherein the meshing end side plate The groove is connected to the high-pressure unloading groove of the meshing end side plate, and the horizontal reference line angle formed by the meshing end side plate groove on both sides of the driving gear shaft and the driven gear shaft and the two gear axes is β; the angle difference formed by the horizontal reference line angle β and the horizontal reference line angle α is consistent with the angle difference θ formed by the driving gear shaft and the driven gear shaft projected on the meshing end side plate plane and the meshing end side plate plane at the meshing end and the meshing end respectively, that is, θ=β-α; the projection line of the oil inlet channel section of the rear cover body in the "8"-shaped inner cavity is parallel to the projection lines of the driving gear shaft and the driven gear shaft in the "8"-shaped inner cavity.

3. A high-pressure helical gear pump according to claim 2, characterized in that: The meshing end side plate is provided with a "3"-shaped groove of the meshing end side plate on the side facing away from the bevel gear, and is interconnected with the meshing end side plate oil inlet groove, the meshing end side plate oil inlet hole and the meshing end side plate high-pressure unloading groove. The outer edge of the "3"-shaped groove of the meshing end side plate and the inner cavity of the rear cover body form a closed meshing end large "3"-shaped compensation area, and a special-shaped retaining ring I and a special-shaped sealing ring I with the same shape as the groove are installed in the "3"-shaped groove of the meshing end side plate; a meshing end side plate "3"-shaped groove is provided on the side facing away from the bevel gear, and is interconnected with the meshing end side plate oil inlet groove, the meshing end side plate oil inlet hole and the meshing end side plate high-pressure unloading groove. The outer edge of the "3"-shaped groove of the meshing end side plate and the inner cavity of the rear cover body form a closed meshing end large "3"-shaped compensation area, and a special-shaped retaining ring II and a special-shaped sealing ring II with the same shape as the groove are installed in the "3"-shaped groove of the meshing end side plate.

4. A high-pressure helical gear pump according to claim 1, characterized in that: The helical gear is an involute helical gear, the overlap coefficient of the helical gear is in the range of 1.5 to 3; the helical angle of the helical gear is in the range of 1° to 45°.

5. A high-pressure helical gear pump according to claim 4, characterized in that: The overlap coefficient of the helical gear is in the range of 1.8 to 2.1; the helical angle of the helical gear is in the range of 8° to 15°.

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